1. Field of the invention
This invention deals with non-metallic cleats for athletic shoes, which cleats provide traction on grass surfaces and provide resistance to wear when used on hard walking surfaces.
2. Description of the related art
It has long been known that metallic cleats on athletic shoes, especially golf shoes, are harmful to the grass surfaces or floors on which they are used and fail to provide traction when worn on hard surfaces. To avoid this problem, a number of plastic golf cleats have been developed. One example of such a golf cleat is that shown in U.S. Pat. No. 6,009,640 to Deacon et al. Such plastic cleats routinely contain a threaded stud for securing the cleat to the sole of a shoe and a main cleat body which contains a convex lower surface containing a plurality of traction ribs. As these cleats are worn on both hard and soft walking surfaces, the hard surfaces have a tendency to wear down the traction ribs of the cleats, making replacement necessary more often than desired. U.S. Pat. No. 6,023,860 to McMullin discloses an athletic shoe cleat which does not adversely affect the turf while providing necessary traction. This cleat contains a hub having an outer flange, an upper surface of the hub containing an attachment stud, and a plurality of traction elements extending substantially laterally from the hub. When used on a turf walking surface, the traction elements extend downwardly to provide traction. When used on a hard surface, the traction elements bend outwardly so that the turf-engaging portions of the traction elements are protected from abrasion and wear. Since the traction elements still bear the full weight of the user, wear of these elements is inevitable. U.S. Pat. No, 6,052,923 to McMullin addresses the problem of wear of the traction element. The cleat of this patent contains an attachment stud, a flange, a plurality of relatively small traction protrusions extending from the flange, and a convex bearing portion extending downwardly from the flange. The small protrusions provide traction while the bearing portion bears the user's weight at all times, on both turf surfaces and hard surfaces. On soft surfaces, the traction protrusions sink into the surface sufficiently to provide traction and to cause the bearing portion to bear weight. On hard surfaces, the resiliency of the traction protrusions causes them to bend so that full weight of the user is carried by bearing portion.